Auth bypass in Zammad
CVE-2026-56723
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, a customer who can view a ticket cannot see internal ticket articles through the article listing API. However, the same customer can directly request an attachment belonging to an internal article via the attachment download endpoint, bypassing article-level authorization. This results in an inconsistency: The article listing hides internal articles from customers. The attachment download only checks the parent ticket, not the article, so the same customer can download the attachment directly. This issue is fixed in version 7.0.2.
Vulnerability class: Broken Access Control
Published · last modified .
EPSS exploit prediction
EPSS: 0.003 (20.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Zammad — versions < 7.0.2